Typically laser weapons mounted on host vehicles have rather complex pointing systems which are required to achieve the desired accuracy. An inner gimble set with high bandwidth and small angular motion, is usually used in conjunction with a coarse gimble set having low bandwidth and large angular motion. Weight, size, and cost problems are usually associated with this type system.
A simplified system (SLAPS) was devised which utilized the natural jitter of a human, pointing a hand held weapon, to produce random boresight to target error angles near zero (patent application Ser. No. 835,815, filed Feb. 3, 1986). When this near zero error angle was detected the laser was fired.
Another system described in a patent application entitled ISLAPS AMPC 4390 (under the same inventors of this disclosure) used this same random occurence of near zero error angles, produced by natural jitter, to point a laser mounted on a vehicle. This system used image correlation to detect the near zero error angles. The correlator would automatically fire the weapon. The ISLAPS could replace the fine gimble on conventional systems reducing size, cost, and weight problems. The system uses tracking mount jitter, atmospheric disturbance, and other factors that normally reduce pointing accuracy to advantage rather than fighting them as a disadvantage.
The ISLAPS system as described in the disclosure mentioned above had a major disadvantage which has been addressed in the subsystem add-on described in this disclosure. The original system could not operate in low light or nightime scenarios. The camera could not produce an image. The subsystem described herein will solve this problem by bouncing an interrogator laser beam off the target to provide the required light.
Addition of this subsystem provides some other distinct advantages/improvements over the original system. Normal day time imaging particularly at longer ranges is greatly improved by the addition of this subsystem because of the potential for range gating. Addition of the interrogator laser also permits operation on the mode described in patent application Ser. No. 835,815. Retro-reflections from optics having a focal plane return the interrogator beam. When these returns exceed threshold levels the negation laser (which is aligned to the interrogator) is fired. This mode has potential for both day and night use.